Related papers: Off-shell Dark Matter: A Cosmological relic of Qua…
In the standard inflationary paradigm the inhomogeneities observed in the CMB arise from quantum fluctuations of an initially homogeneous and isotropic vacuum state. This picture suffers from two well-known weaknesses. First, it assumes…
Planckian Interacting Dark Matter (PIDM) is a minimal scenario of dark matter assuming only gravitational interactions with the standard model and with only one free parameter, the PIDM mass. PIDM can be successfully produced by…
We review some recent proposals for relativistic models of dark matter in the context of bimetric gravity. The aim is to solve the problems of cold dark matter (CDM) at galactic scales, and to reproduce the phenomenology of the modified…
Cold dark matter may be a fluid (or plasma) residing in a strongly-interacting hidden sector, rather than a population of weakly-coupled particles. Such a scenario admits a holographic description in terms of a cosmological braneworld…
We discuss bulk viscous cosmological models. Since the bulk viscous pressure is negative, viable viscous cosmological scenarios with late time accelerated expansion can in principle be constructed. After discussing some alternative models…
Analytic formulas reproducing the warm dark matter (WDM) primordial spectra are obtained for WDM particles decoupling in and out of thermal equilibrium which provide the initial data for WDM non-linear structure formation. We compute and…
The leading tensions to the collisionless cold dark matter (CDM) paradigm are the "small-scale controversies", discrepancies between observations at the dwarf-galactic scale and their simulational counterparts. In this work we consider…
We investigate the nightmare scenario of dark sectors that are made of non-abelian gauge theories with fermions, gravitationally coupled to the Standard Model (SM). While testing these scenarios is experimentally challenging, they are…
For almost two decades the properties of "dwarf" galaxies have challenged the Cold Dark Matter (CDM) paradigm of galaxy formation. Most observed dwarf galaxies consists of a rotating stellar disc embedded in a massive DM halo with a near…
We propose that cosmological magnetic fields generated in regions of finite spatial dimensions may manifest themselves in the global dynamics of the Universe as `dark energy'. We test our model in the context of spatially flat cosmological…
In previous work [L. Blanchet and A. Le Tiec, Phys. Rev. D 80, 023524 (2009)], motivated by the phenomenology of dark matter at galactic scales, a model of dipolar dark matter (DDM) was introduced. At linear order in cosmological…
We propose that dark matter is not yet another new particle in nature, but that it is a remnant of quantum gravitational effects on known fields. We arrive at this possibility in an indirect and surprising manner: by considering retarded,…
Standard lore states that there is tension between the need to accommodate the relic density of a weakly interacting massive particle and direct searches for dark matter. However, the estimation of the relic density rests on an…
We propose a revised cosmological scenario that extends the $\Lambda$ Cold Dark Matter ($\Lambda$CDM) framework by incorporating metric $f(R)$ gravity in the Jordan frame. In this model, the dark energy component arises from a non-minimally…
We study the possibility of Late Forming Dark Matter (LFDM), where a scalar field, previously trapped in a metastable state by thermal or finite density effects, begins to oscillate near the era matter-radiation equality about its true…
We describe a general scenario, dubbed "Inflatable Dark Matter", in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early universe. The overproduction of dark matter that is…
A limiting temperature of a species can cause the Universe to asymptote to it yielding a deSitter (dS) phase due to macroscopic emergent behavior. The limiting temperature is generic for theories slightly shifted from their conformal point.…
The concordance Lambda Cold Dark Matter (Lambda-CDM) model for the formation of structure in the Universe, while remarkably successful at describing observations of structure on large scales, continues to be challenged by observations on…
Cold Dark Matter (CDM) models struggle to match the observations at galactic scales. The tension can be reduced either by dramatic baryonic feedback effects or by modifying the particle physics of CDM. Here, we consider an ultra-light…
Increasingly stringent limits from LHC searches for new physics, coupled with lack of convincing signals of weakly interacting massive particle (WIMP) in dark matter searches, have tightly constrained many realizations of the standard…